They were worried that years - and possibly decades - of prospective appeals would prolong their agony.

The double bombing carried out by the brothers killed three people and wounded 264 others, including 17 who lost limbs, near the finish line at the northeastern city’s popular marathon.

Tsarnaev went on the run and was arrested four days later, hiding and injured in a grounded boat on which he had scrawled a bloody message defending the attacks as a means to avenge US wars in Iraq and Afghanistan.

He showed no emotion as the court clerk took 20 minutes to read out the verdict form that culminated in the death penalty verdict. He stood hands clasped before him, wearing an open-necked shirt and a dark blazer.

The decision caps a 12-week trial that relived the horror of the attacks through grisly videos and heartbreaking testimony from those who lost limbs and loved ones.

US Attorney General Loretta Lynch called the sentence a “fitting punishment,” while prosecutors and law enforcement in Boston said they were satisfied, but urged commemoration rather than celebration.